Special Counsel Robert Mueller recommended that a federal judge to sentence George Papadopoulos, a former campaign aide of US President Donald Trump, to up to six months in prison for lying to investigators in relation to the ongoing Russia meddling probe.

"The government does not take a position with respect to a particular sentence to be imposed, but respectfully submits that a sentence of incarceration, within the applicable guidelines range of 0 to 6 months' imprisonment, is appropriate and warranted," Mueller wrote on Friday in a government sentencing memorandum to the US District Court for the District of Columbia. "The defendant's crime was serious and caused damage to the government's investigation into Russian interference in the 2016 presidential election," Mueller added.